In A Chopin wanted to start the tempo indication of the final section of the Fantasy with the word Molto, which he, however, deleted, hence Allo assai, written at the same height, is inevitably only just in the 2nd half of the bar. Both GE and [FC] (→FE→EE) considered this position to have been forced by the deletion, and the indication was placed at the beginning of the bar, which we adopt to the main text, since it is most probably an accurate interpretation. Nevertheless, as the text of A we provide the literal interpretation, since numerous pianists begin this fragment slower, achieving a fast tempo only just in the 2nd half of the bar (and often much later), which sounds natural in this context. Therefore, Chopin could have assumed this forced shift to be realistic, hence acceptable.
Compare the passage in the sources»
category imprint: Differences between sources; Corrections & alterations; Source & stylistic information
issues: Corrections in A, GE revisions, Deletions in A, FE revisions, Centrally placed marks
notation: Verbal indications